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Observations on the nature and origin of lipids in the small intestine of the sheep

Published online by Cambridge University Press:  09 March 2007

Aileen M. Lennox
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen
A. K. Lough
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen
G. A. Garton
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen
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Abstract

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1. Total lipids were extracted from digesta obtained from the rumen, abomasum and upper small intestine (jejunum) of each of four slaughtered sheep. The lipids were fractionated into unesterified fatty acids, neutral lipids and phospholipids and the proportional contribution of each fraction to the total fatty acids was determined.

2. The contribution made by phospholipids to the total fatty acids in the digesta showed a marked increase in the samples from the small intestine compared with those from the rumen and abomasum. This increase was apparently due to the presence of biliary phospholipids.

3. Total lipids and conjugated bile acids were extracted from sheep bile, the lipids were fractionated and their fatty-acid composition was determined. Phospholipids predominated and these consisted mainly of phosphatidylcholine, together with some lysophosphatidylcholine.

4. Both phospholipids contained significant amounts of unsaturated C18 components which could account, at least in part, for the previously reported increament to the proportion of these acids in the digesta when it enters the upper jejunum.

5. The overall fatty acid compositions of the two biliary phospholipids were very similar and, in common with other naturally occurring phosphatidylcholines, the fatty acids present in position 2 of the phosphatidylcholine of bile were found to consist almost entirely of unsaturated components.

6. Total lipids and conjugated bile acids were extracted from samples of digesta obtained from three sheep with cannulas in different positions in the jejunum. Analysis of the lipids indicated that biliary phospholipids, in particular phosphatidylcholine, underwent progressive hydrolysis in the intestinal lumen.

7. The distribution of conjugated bile acids, unesterified fatty acids and phospholipids between the solid (particulate) and liquid (micellar) phases of the intestinal digesta was determined. These chyme constituents were, for the most part, associated with the particulate matter and thus, at any given time, it appears that only a small fraction of the total fatty acids is available for absorption in micellar form. It is suggested that the micellar solubilization of fatty acids may be facilitated by the presence of lysophosphatidylcholine.

Type
Research Article
Copyright
Copyright © The Nutrition Society 1968

References

Adams, E. P. & Heath, T. J. (1963). Biochim. biophys. Acta 70, 88.CrossRefGoogle Scholar
Ash, R. W. (1962). Anim. Prod. 4, 309.Google Scholar
Bath, I. H. & Hill, K. J. (1967). J. agric. Sci., Camb. 68, 139.CrossRefGoogle Scholar
Bligh, E. G. & Dyer, W. J. (1959). Can. J. Biochem. Physiol. 37, 911.CrossRefGoogle Scholar
De Haas, G. H. & Van Deenen, L. L. M. (1965). Biochim. biophys. Acta 106, 315.CrossRefGoogle Scholar
Dole, V. P., James, A. T., Webb, J. P. W., Rizack, M. A. & Sturman, M. F. (1959). J. clin. Invest. 38, 1544.CrossRefGoogle Scholar
Duncan, W. R. H. & Garton, G. A. (1962). J. Lipid Res. 3, 53.CrossRefGoogle Scholar
Duncan, W. R. H. & Garton, G. A. (1963). Biochem. J. 89, 414.CrossRefGoogle Scholar
Eastwood, M. A. & Boyd, G. S. (1967). Biochim. biophys. Acta 137, 393.CrossRefGoogle Scholar
Feliński, L., Garton, G. A., Lough, A. K. & Phillipson, A. T. (1964). Biochem. J. 90, 154.CrossRefGoogle Scholar
Garton, G. A. (1965). In Physiology of Digestion in the Ruminant, p. 390. [Dougherty, R. W., editor.] Washington, DC.: Butterworths.Google Scholar
Garton, G. A. (1967). Wld Rev. Nutr. Diet. 7, 225.CrossRefGoogle Scholar
Garton, G. A. & Duncan, W. R. H. (1957). Biochem. J. 67, 340.CrossRefGoogle Scholar
Garton, G. A., Duncan, W. R. H. & Lough, A. K. (1961). Biochim. biophys. Acta 47, 592.CrossRefGoogle Scholar
Hofmann, A. F. (1964). In New Biochemical Separations, p. 266. [James, A. T. and Morris, L. J., editors]. London: D. Van Nostrand Co. Ltd.Google Scholar
Hofmann, A. F. (1966). Gastroenterology 50, 56.CrossRefGoogle Scholar
Leat, W. M. F. (1965). Biochem. J. 94, 21P.Google Scholar
Lennox, A. M. & Garton, G. A. (1968). Br. J. Nutr. 22, 247.CrossRefGoogle Scholar
Lennox, A. M., Lough, A. K. & Garton, G. A. (1965). Biochem. J. 96, 27P.Google Scholar
Long, C. & Penny, I. F. (1957). Biochem. J. 65, 382.CrossRefGoogle Scholar
Malins, D. C. & Mangold, H. K. (1960). J. Am. Oil Chem. Soc. 37, 576.CrossRefGoogle Scholar
McCarthy, R. D. (1962). In Use of Radioisotopes in Animal Biology and the Medical Sciences. Vol. 2, p. 151. London and New York: Academic Press Inc.Google Scholar
Nilsson, A. & Borgström, B. (1967). Biochim. biophys. Acta 137, 240.CrossRefGoogle Scholar
Senior, J. R. (1964). J. Lipid Res. 5, 495.CrossRefGoogle Scholar
Slotboom, A. J., De Haas, G. H. & Van Deenen, L. L. M. (1963). Recl. Trav. chim. Pays-Bas Belg. 82, 469.CrossRefGoogle Scholar
Van den Bosch, H. & Van Deenen, L. L. M. (1965). Biochim. biophys. Acta 106, 326.CrossRefGoogle Scholar
Wagner, H., Hörhammer, L. & Wolff, P. (1961). Biochem. Z. 334, 175.Google Scholar
Ward, P. F. V., Scott, T. W. & Dawson, R. M. C. (1964). Biochem. J. 92, 60.CrossRefGoogle Scholar